摘要
为提高生物质在大型煤粉电站锅炉直接掺烧的安全性和经济性,分析了多种典型生物质与典型煤种的煤质及燃烧性能差异,论述了掺烧生物质后对锅炉主机及辅机的设备适应性及运行的影响,同时分析了国内外煤粉锅炉直接掺烧生物质的典型掺烧方式及特点。结果表明,生物质具有水分高、密度低、挥发分和氧含量高、硫含量低、环保性能好等优势。大型煤粉电站锅炉掺烧生物质时,需充分考虑掺烧生物质对机组设备的适应性及运行参数的影响,重点考虑生物质的全水分、发热量、灰熔融温度和灰成分中Fe 2 O 3、CaO、MgO和K 2 O等碱性氧化物对燃料制备、储存和输送,锅炉效率,制粉系统出力,带负荷能力及锅炉的结渣、沾污和腐蚀等影响。通过优选生物质种类,掺烧5%~10%的成型生物质对大型煤粉电站锅炉主机、燃烧系统、制粉系统及其他辅机系统运行无明显影响。综合考虑技术可行性、经济性及运行安全性,采用独立喷燃工艺2即利用锅炉备用制粉系统实现生物质独立掺烧的经济性更高。为防止生物质燃烧器的烧损,要求磨制生物质燃料的磨煤机进口风温在100℃以内,以保证磨出口一次风温不超过50℃,以40~45℃为宜。当生物质比例低或掺烧时间短时,可考虑共磨掺烧方案,但需严重控制生物质自燃,确保生物质掺烧的安全性。因此通过优选生物质种类和掺烧方式、控制掺烧比例、优化运行参数等可保证大型煤粉电站锅炉直接掺烧生物质的安全运行。在大容量高参数的煤粉锅炉上直接掺烧生物质具有投资和占地面积少、无或少量设备改造、热效率高、掺烧不受季节影响等优势,目前制约其大规模推广应用的主要原因是生物质不受人工干预的准确计量。
In order to improve the safety and economy of the direct blending biomass in large pulverized coal boilers,the differences of coal quality and combustion performance between typical biomass and coals were analyzed,and the influence of biomass blending on equipment adaptability and operation of main and auxiliary boilers was discussed comprehensively in this paper.Meanwhile,typical combustion modes and characteristics of directly blending biomass at home and abroad were comprehensively studied.The results show that the biomass had the advantages of high moisture,low density,high V daf and oxygen,low sulfur,which has excellent environmental protection performance.When the large-scale pulverized coal-fired boiler is mixed with biomass,the influence on operation and the adaptability with auxiliary equipment need to be considered,especially the total moisture,calorific value,ash melting temperature,alkaline oxides such as Fe 2 O 3,CaO,MgO and K 2 O in ash composition on fuel preparation,storage and transportation,boiler efficiency,output of pulverizing system,load capacity and boiler slagging,fouling and corrosion and so on.Generally,the blending 5%-10%formed biomass has no significant impact on the operation of the boiler,combustion system,pulverizing system and other auxiliary systems,through the optimization of biomass types.Considering the technical feasibility,economy and operation safety,it is more economical to adopt independent combustion process 2,i.e.to use the standby pulverizing system of boilers to realize the independent combustion of biomass.In order to prevent burning-out of biomass burner,it is required that the inlet air temperature of biomass mill should be less than 100℃to ensure the primary air temperature of the mill outlet lower than 50℃,and 40-45℃is appropriate.The co-grinding blending process can be considered when the biomass ratio is low or the blending time is short,but the spontaneous combustion of biomass needs to be controlled strictly to ensure the safety of biomass blending.Therefore,the safe operation of large-scale pulverized coal power plant boilers when blending directly with biomass can be guaranteed by optimizing the types of biomass,appropriate blending mode,blending proportion control and optimization of operation parameters.Blending biomass directly on large capacity and high parameter pulverized coal boilers has the advantages of less investment,less area covered,less or zero equipment modification,high thermal efficiency and no seasonal influence,while the main reason that restricts its large-scale application is the precisely measurement without human involvement at present.
作者
刘家利
王志超
邓凤娇
屠竞毅
方顺利
LIU Jiali;WANG Zhichao;DENG Fengjiao;TU Jingyi;FANG Shunli(Xi'an Thermal Power Research Institute Co.,Ltd.,Xi'an 710054,China;Xi'an Yitong Thermal Technology Services Co.,Ltd.,Xi'an 710032,China)
出处
《洁净煤技术》
CAS
2019年第5期17-23,共7页
Clean Coal Technology
基金
山西省科技重大专项资助项目(MD2015-03)
关键词
煤粉电站锅炉
生物质
掺烧
掺烧比例
适应性
pulverized coal fired power plant boiler
biomass
direct-blending
blending ratio
adaptability
